The FBI’s July raid on former Trump campaign chairman Paul Manafort’s Virginia home lasted 10 hours and involved a dozen federal agents, who seized documents labeled “attorney-client,” according to a source close to the investigation.

The July raid was first reported earlier this month, but the new details reflect the intensity and scope of the search, which the source described as “heavy-handed, designed to intimidate.” Elements of the account were backed up by a second individual also not authorized to speak on the record.